Mitel MIVOICE OFFICE 250, Installation And Administration Manual, Page: 365 / 585

Installation
337
Installing SIP Gateways
Support is provided in the system for local Public Switched Telephone Network (PSTN) connectivity
using the IP resources in the MiVoice Office 250 controller and a third-party Session Initiated Protocol
(SIP) gateway. The IP Resource application expands the support of 25 IP phones/Single Port
LSAs/SoftPhones to include Loop Start Adapters (Single Port LSAs). Support for IP-based local loop
requires no software feature units.
Up to 25 IP resource ports can be programmed to be loop start adapter ports (SIP/MGCP gateway
trunks). The IP Resource application statically maps IP resources on a one-to-one, non-blocking
basis for each loop start port within the SIP/MGCP device.
For a current list of compatible SIP gateways, refer to KB article 09-4940-00056 on the Mitel
Knowledge Base Center
(http://domino1.mitel.com/prodsupp/prodsupkb.nsf/WebSearchForm?OpenForm). You must first
log on to Mitel Online (http://portal.mitel.com/wps/myportal/MOLHome) in order to access the KB
using this link.
When configured with a SIP gateway, you can program the system so that when an Emergency
Number is dialed from an IP device, the calling name and number associated with the IP device,
not the system, is sent to the emergency call operators.
With regard to the
Service Type
feature, call processing supports Caller ID on the Single Port LSA.
The Single Port LSA has built-in Caller ID receivers. It does not use shared Caller ID resources
within the system. The resource manager within Call Processing is modified to have Caller ID
receivers as an attribute for this device type and to use the local Caller ID receiver. If the service
type is set to Caller ID, Caller ID messages are passed up through the IP resource application to
Call Processing. By default, it is set to None.
WARNING
Possible Delay in Local Emergency Response to Remote Sites.
IP and SIP phone users should be alerted to the following hazardous situations:
• If an Emergency Call phone number is dialed from an IP or SIP phone located at a remote site that is
not
equipped with a correctly configured gateway, the call will be placed from the location where
system chassis is installed rather than from the location where the emergency call is made.
In this situation, emergency responders may be dispatched to the wrong location. To minimize the risk
of remote site users misdirecting emergency responders, Mitel recommends regular testing of
SIP/MGCP gateway trunk(s) for dial tone.
• If uninterruptible power supply (UPS) protection has not been installed as part of the MiVoice Office
250, IP and SIP phones will
not
operate when electrical power fails either at remote sites or at the
main system location.
To place calls during a power failure in this situation, IP and SIP phone users can only use a single line
phone connected to one of the power failure bypass circuits built-in to the system chassis. If a phone
connected to a power failure bypass circuit is
not
available, users should make emergency calls from a
local phone
not
connected to the system. For details about the Power Failure Bypass feature, refer to
the MiVoice Office 250 Features and Programming Guide .